In a system to transmit a non-compressed (baseband) video signal with cable or wireless technique, the maximum transmission bit rate of the transmission path thereof has an upper limit, and a non-compressed video signal of a bit rate above the upper limit transmission bit rate cannot be transmitted.
Currently, baseband transmission systems are stipulated to transmit up to 1920×1080 60p. However, hereafter, graphics cards of a PCs (Personal Computer) which correspond to standards of QWXGA (2560×1600), QSXGA (2560×2048), QUXGA (3200×2400), and QWUXGA (3840×2400) are conceivable, and also, with broadcasting/cinemas, high-precision screens such as 4K×2K (4096×2048) or 4×2K (3840×2160) are conceivable.
In the event thereof, transmission of a non-compressed video signal with a resolution exceeding 1920×1080 is required. However, with the current baseband transmission system, as described above, transmitting up to 1920×1080 60p is stipulated, and in order to transmit a non-compressed video signal with a resolution exceeding 1920×1080 requires some sort of data compression means.
For example, Patent Document 1 discloses controlling the transmission bit rate by changing the modulation method of changing the transmission frequency, in the event of wireless transmission. Also, for example, Patent Document 2 discloses appending identification data of a communication mode such as band compression or security processing or the like, and on the transmission arriving side, performing transmission-arriving processing based on the communication mode identification data.
Also, for example, Patent Document 3 discloses, in a bi-directional image communication system having a client and server that encodes a video using a video compression method that generates key frames that are compressed within the frame and interpolation frames that are compressed between frames, effectively using a bandwidth between server and client by determining a refresh rate value for video encoding with the client, based on the transmission state from the server to the client.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2007-370229    Patent Document 2: Japanese Unexamined Patent Application Publication No. 11-8626    Patent Document 3: Japanese Unexamined Patent Application Publication No. 2006-109011